1. Technical Field
The present invention relates generally to a wireless power transmission/reception apparatus and method, and, more particularly, to a wireless power transmission/reception apparatus and method which enable the active detection of the reception environment of the wireless power transmission/reception apparatus without using a separate wireless communication device.
2. Description of the Related Art
With the development of wireless communication technology, ubiquitous information environments enabling anyone to exchange desired information anytime and anywhere have been implemented. However, most communication information devices still depend on batteries and are supplied with power through power cords, and thus the use of communication information devices is limited. Therefore, the environment of a wireless information network cannot be actually freed from this limitation until the problem of terminal power is solved.
In order to solve this problem, various types of technologies for transmitting power in a wireless manner have been developed.
First, representative technologies may include radio reception technology using microwaves, magnetic induction technology using a magnetic field, and magnetic resonance technology using energy conversion between a magnetic field and an electric field.
Radio reception technology is advantageous because microwaves are radiated into the air through an antenna, and thus long-distance power transmission is made possible. However, radio reception technology has high radiation loss due to the consumption of power by the air, and thus the efficiency of power transmission is limited.
Furthermore, magnetic induction technology is a technology based on magnetic energy coupling using the primary coil of a transmitting end and the secondary coil of a receiving end, and is advantageous in that the efficiency of power transmission is high. However, magnetic induction technology is disadvantageous in that the primary coil of the transmitting end and the secondary coil of the receiving end must be located adjacent to each other within a short distance of about several mm so as to transmit power, in that the efficiency of power transmission rapidly changes according to the alignment of the primary coil of the transmitting end and the secondary coil of the receiving end, and in that the amount of heat generated is large.
Therefore, magnetic resonance technology that is similar to magnetic induction technology has recently been developed, but it is configured to concentrate energy on a specific resonant frequency determined by an inductor L and a capacitor C, and thus to transmit power in the form of magnetic energy. This is advantageous because a relatively large amount of power can be transmitted even a distance of several meters, but requires high resonance characteristics (a high quality factor).
That is, magnetic induction technology is disadvantageous because the efficiency of power transmission rapidly changes depending on whether impedance matching has been achieved or whether the resonant frequencies of the LC circuits of the transmitting and receiving ends are identical to each other.
Conventional magnetic induction technology deals with the above problems via communication between the transmitting end and the receiving end by installing transceivers both on the transmitting and receiving ends. However, when the transceivers are installed separately, problems arise in that the cost of wireless power transmission and reception units increases and the construction of the apparatus is complicated.